renal cortex the granular outer layer of the kidney, composed mainly of glomeruli and convoluted tubules, extending in columns between the pyramids that constitute the renal medulla.

striate cortex part of the occipital lobe that receives the fibers of the optic radiation and serves as the primary receiving area for vision. Called also first visual area.

visual cortex the area of the occipital lobe of the cerebral cortex concerned with vision; the striate cortex is also called the first visual area, and the adjacent second and third visual areas serve as its association areas.

ce·re·bral cor·tex

[TA]

the gray cellular mantle (1-4 mm thick) covering the entire surface of the cerebral hemisphere of mammals; characterized by a laminar organization of cellular and fibrous components such that its nerve cells are stacked in defined layers varying in number from one, as in the archicortex of the hippocampus, to five or six in the larger neocortex; the outermost (molecular or plexiform) layer contains very few cell bodies and is composed largely of the distal ramifications of the long apical dendrites issued perpendicularly to the surface by pyramidal and fusiform cells in deeper layers. From the surface inward, the layers as classified in K. Brodmann's parcellation are: 1) molecular layer [TA]; 2) external granular layer [TA]; 3) external pyramidal layer [TA]; 4) internal granular layer [TA]; 5) internal pyramidal layer [TA]; and 6) multiform layer [TA], many of which are fusiform. This multilaminate organization is typical of the neocortex (homotypic cortex; isocortex [TA] in O. Vogt terminology), which in humans covers the largest part by far of the cerebral hemisphere. The more primordial heterotypic cortex or allocortex (Vogt) has fewer cell layers. A form of cortex intermediate between isocortex and allocortex, called juxtallocortex (Vogt), covers the ventral part of the cingulate gyrus and the entorhinal area of the parahippocampal gyrus. On the basis of local differences in the arrangement of nerve cells (cytoarchitecture), Brodmann outlined 47 areas in the cerebral cortex that, in functional terms, can be classified into three categories: motor cortex (areas 4 and 6), characterized by a poorly developed internal granular layer (agranular cortex) and prominent pyramidal cell layers; sensory cortex, characterized by a prominent internal granular layer (granular cortex or koniocortex) and comprising the somatic sensory cortex (areas 1-3), the auditory cortex (areas 41 and 42), and the visual cortex (areas 17-19); and association cortex, the vast remaining expanses of the cerebral cortex.

cerebral cortex

cerebral cortex

Etymology: L, cerebrum + cortex, bark

a layer of neurons and synapses (gray matter) on the surface of the cerebral hemispheres, folded into gyri with about two thirds of its area buried in fissures. It integrates higher mental functions, general movement, visceral functions, perception, and behavioral reactions. It has been classified in many different ways. Research has described more than 200 areas on the basis of differences in myelinated fiber patterns and has defined 47 separate function areas with different cell designs. For example, stimulation of the precentral cortex or motor area with electrodes causes contractions of voluntary muscles. Destruction of a motor speech area in the frontal operculum causes motor aphasia or speech defects despite healthy, intact vocal organs. Stimulation of the frontal area affects circulation, respiration, pupillary reaction, and other visceral activity. Also called pallium. See also cerebrum.

cerebral cortex

Neurology The outer portion of the brain, the neocortex consisting of gray-colored layers of nerve cells, and the interconnecting neural circuitry, which is intimately linked to cognition. See Limbic system.

ce·re·bral cor·tex

(ser'ĕ-brăl kōr'teks) [TA]

The gray cellular mantle (1-4 mm thick) covering the entire surface of the cerebral hemisphere of mammals; characterized by a laminar organization of cellular and fibrous components such that its nerve cells are stacked in defined layers varying in number from one, as in the archicortex of the hippocampus, to five or six in the larger neocortex; the outermost (molecular or plexiform) layer contains very few cell bodies and is composed largely of the distal ramifications of the long apical dendrites issued perpendicularly to the surface by pyramidal and fusiform cells in deeper layers. From the surface inward, the layers as classified in K. Brodmann's parcellation are: 1) molecular or plexiform layer; 2) outer granular layer; 3) pyramidal cell layer; 4) inner granular layer; 5) inner pyramidal layer (ganglionic layer); and 6) multiform cell layer, many of which are fusiform. This multilaminate organization is typical of theneocortex (homotypic cortex; isocortex in O. Vogt's terminology), which in humans covers the largest part by far of the cerebral hemisphere. The more primordial heterotypic cortex or allocortex (Vogt) has fewer cell layers. A form of cortex intermediate between isocortex and allocortex, called juxtallocortex (Vogt), covers the ventral part of the cingulate gyrus and the entorhinal area of the parahippocampal gyrus. On the basis of local differences in the arrangement of nerve cells (cytoarchitecture), Brodmann outlined 47 areas in the cerebral cortex that, in functional terms, can be classified into three categories: motor cortex (Brodmann areas 4 and 6), characterized by a poorly developed inner granular layer (agranular cortex) and prominent pyramidal cell layers; sensory cortex, characterized by a prominent inner granular layer (granular cortex or koniocortex) and comprising the somatic sensory cortex (Brodmann areas 1-3), the auditory cortex (Brodmann areas 41 and 42), and the visual cortex (Brodmann areas 17-19); and association cortex, the vast remaining expanses of the cerebral cortex. See also: Brodmann areas

cerebral cortex

The grey outer layer of the cerebral hemispheres, consisting of the layered masses of nerve cell bodies which perform the higher neurological functions.

cerebral cortex

the intricately folded outer layer of the CEREBRUM, being a layer of GREYMATTER forming the most superficial layer of the roof of the CEREBRAL HEMISPHERES in the forebrain of higher vertebrates. The cerebral cortex consists of millions of densely packed nerve cells and is rich in synapses. It is present in reptiles, birds and mammals and in some lower vertebrates. see BRAIN. In man, the cerebral cortex forms about 40% of the brain by weight.

Cerebral cortex

ce·re·bral cor·tex

(ser'ĕ-brăl kōr'teks) [TA]

The gray cellular mantle (1-4 mm thick) covering the entire surface of the cerebral hemisphere of mammals characterized by a laminar organization of cellular and fibrous components. Based on local differences in the arrangement of nerve cells, there are multiple areas that, on the basis of function, can be categorized into three general groups: motor cortex, sensory cortex, and association cortex.

cerebral cortex,

n a thin layer of gray matter on the surface of the cerebral hemisphere, folded into gyri with about two thirds of its area buried in fissures. It integrates higher mental functions, general movement, visceral functions, perception, and behavioral reactions.

cerebral

arterial blood supply reaches the anterior, middle and posterior cerebral arteries via the circle of Willis, in some species originating directly from the internal carotid and basilar arteries, in others via an interposed rete mirabile. See also blood-brain barrier, blood-CSF barrier, cerebrospinal fluid.

cerebral contusion

contusion of the brain following a head injury. See also cerebral contusion.

the clinical signs associated with lesions of the cerebral cortex and diencephalon. They include behavioral or mental change, abnormal movements such as circling and head pressing, deficits in contralateral postural responses and sometimes visual impairment.

cerebral dura mater

the membranous cover around the brain. Endosteal and meningeal layers are separated only by the cranial venous sinuses. Continuous with the spinal cord dura and the sheaths of the spinal nerves. Has three internal folds which separate sections of the brain. See falx cerebri, tentorium cerebelli, sella turcica.

cerebral edema, cytotoxic

caused by neurotoxins, this edema is intracellular.

cerebral edema, generalized

when all cerebral tissues are affected as in disturbances which create marked differences from normal of sodium and potassium ion concentration in tissues.

cerebral edema, interstitial

edema of the central white matter as in hydrocephalus affecting the brain and hydromyelia affecting the spinal cord.

cerebral edema, vasogenic

when the edema is intercellular and due usually to damage to the vascular endothelium.

cerebral flush

the congestion of the cerebral vessels causing a pink coloration; of infections by Babesia bovis and B. bigemina it is the former in which the cerebral flush occurs.

cerebral gyri

convolutions on the surface of the cerebrum.

cerebral hemisphere

symmetrical right and left halves of the cerebrum divided by the longitudinal fissure.

cerebral peduncle

see cerebral peduncle.

cerebral pia mater

thin connective tissue membrane that lies closely against the cerebral surface and carries blood vessels into the tissues of the brain.

cerebral piriform lobe

on the floor of the brain medial to the lateral olfactory tract.

cerebral pole

frontal (rostral) and occipital (caudal) poles of the cerebrum.

cerebral substantia nigra

occupies the interior of the cerebral peduncles.

cerebral syndrome

characterized by abnormal mental state, abnormal movements such as pacing or head pressing, visual impairment and seizures.

cerebral theileriosis

infection with Theileria parva or aberrant forms of T. taurotragi originating from the eland. Called also turning sickness.

cerebral vascular accident (CVA)

a disorder of the blood vessels serving the cerebrum, resulting from an impaired blood supply to parts of the brain. Called stroke in humans.

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